Gary Greaves (Tohoku)

Edge-Signed Graphs With Smallest Eigenvalue Greater Than −2

Abstract for the Combinatorics Seminar
2015 October 20

Graphs and edge-signed graphs whose eigenvalues are at least −2 have enjoyed a great amount of interest from the mathematical community. In this talk I will present a recent classification of edge-signed graphs having smallest eigenvalue greater than −2 and I will present a proof of a conjecture of Hoffman that was stated in the 1970s. Hoffman's conjecture is related to his study of the limit points of the smallest eigenvalue of graphs.


To the Combinatorics Seminar Web page.